<?php
//dezend by http://www.yunlu99.com/ QQ:270656184
defined('BASEPATH') || exit('No direct script access allowed');
class CI_Session_files_driver extends CI_Session_driver implements SessionHandlerInterface
{
	/**
	 * Save path
	 *
	 * @var	string
	 */
	protected $_save_path;
	/**
	 * File handle
	 *
	 * @var	resource
	 */
	protected $_file_handle;
	/**
	 * File name
	 *
	 * @var	resource
	 */
	protected $_file_path;
	/**
	 * File new flag
	 *
	 * @var	bool
	 */
	protected $_file_new;
	/**
	 * Validate SID regular expression
	 *
	 * @var	string
	 */
	protected $_sid_regexp;
	/**
	 * mbstring.func_overload flag
	 *
	 * @var	bool
	 */
	static protected $func_overload;

	public function __construct(&$params)
	{
		parent::__construct($params);

		if (isset($this->_config['save_path'])) {
			$this->_config['save_path'] = rtrim($this->_config['save_path'], '/\\');
			ini_set('session.save_path', $this->_config['save_path']);
		}
		else {
			log_message('debug', 'Session: "sess_save_path" is empty; using "session.save_path" value from php.ini.');
			$this->_config['save_path'] = rtrim(ini_get('session.save_path'), '/\\');
		}

		$this->_sid_regexp = $this->_config['_sid_regexp'];
		isset(self::$func_overload) || (self::$func_overload = extension_loaded('mbstring') && ini_get('mbstring.func_overload'));
	}

	public function open($save_path, $name)
	{
		if (!is_dir($save_path)) {
			if (!mkdir($save_path, 448, true)) {
				throw new Exception('Session: Configured save path \'' . $this->_config['save_path'] . '\' is not a directory, doesn\'t exist or cannot be created.');
			}
		}
		else if (!is_writable($save_path)) {
			throw new Exception('Session: Configured save path \'' . $this->_config['save_path'] . '\' is not writable by the PHP process.');
		}

		$this->_config['save_path'] = $save_path;
		$this->_file_path = $this->_config['save_path'] . DIRECTORY_SEPARATOR . $name . ($this->_config['match_ip'] ? md5($_SERVER['REMOTE_ADDR']) : '');
		return $this->_success;
	}

	public function read($session_id)
	{
		if ($this->_file_handle === NULL) {
			$this->_file_new = !file_exists($this->_file_path . $session_id);

			if ($this->_file_handle = fopen($this->_file_path . $session_id, 'c+b') === false) {
				log_message('error', 'Session: Unable to open file \'' . $this->_file_path . $session_id . '\'.');
				return $this->_failure;
			}

			if (flock($this->_file_handle, LOCK_EX) === false) {
				log_message('error', 'Session: Unable to obtain lock for file \'' . $this->_file_path . $session_id . '\'.');
				fclose($this->_file_handle);
				$this->_file_handle = NULL;
				return $this->_failure;
			}

			$this->_session_id = $session_id;

			if ($this->_file_new) {
				chmod($this->_file_path . $session_id, 384);
				$this->_fingerprint = md5('');
				return '';
			}
		}
		else if ($this->_file_handle === false) {
			return $this->_failure;
		}
		else {
			rewind($this->_file_handle);
		}

		$session_data = '';
		$read = 0;

		for ($length = filesize($this->_file_path . $session_id); $read < $length; $read += self::strlen($buffer)) {
			if (($buffer = fread($this->_file_handle, $length - $read)) === false) {
				break;
			}

			$session_data .= $buffer;
		}

		$this->_fingerprint = md5($session_data);
		return $session_data;
	}

	public function write($session_id, $session_data)
	{
		if (($session_id !== $this->_session_id) && (($this->close() === $this->_failure) || ($this->read($session_id) === $this->_failure))) {
			return $this->_failure;
		}

		if (!is_resource($this->_file_handle)) {
			return $this->_failure;
		}
		else if ($this->_fingerprint === md5($session_data)) {
			return !$this->_file_new && !touch($this->_file_path . $session_id) ? $this->_failure : $this->_success;
		}

		if (!$this->_file_new) {
			ftruncate($this->_file_handle, 0);
			rewind($this->_file_handle);
		}

		if (0 < ($length = strlen($session_data))) {
			for ($written = 0; $written < $length; $written += $result) {
				if (($result = fwrite($this->_file_handle, substr($session_data, $written))) === false) {
					break;
				}
			}

			if (!is_int($result)) {
				$this->_fingerprint = md5(substr($session_data, 0, $written));
				log_message('error', 'Session: Unable to write data.');
				return $this->_failure;
			}
		}

		$this->_fingerprint = md5($session_data);
		return $this->_success;
	}

	public function close()
	{
		if (is_resource($this->_file_handle)) {
			flock($this->_file_handle, LOCK_UN);
			fclose($this->_file_handle);
			$this->_file_handle = $this->_file_new = $this->_session_id = NULL;
		}

		return $this->_success;
	}

	public function destroy($session_id)
	{
		if ($this->close() === $this->_success) {
			if (file_exists($this->_file_path . $session_id)) {
				$this->_cookie_destroy();
				return unlink($this->_file_path . $session_id) ? $this->_success : $this->_failure;
			}

			return $this->_success;
		}
		else if ($this->_file_path !== NULL) {
			clearstatcache();

			if (file_exists($this->_file_path . $session_id)) {
				$this->_cookie_destroy();
				return unlink($this->_file_path . $session_id) ? $this->_success : $this->_failure;
			}

			return $this->_success;
		}

		return $this->_failure;
	}

	public function gc($maxlifetime)
	{
		if (!is_dir($this->_config['save_path']) || (($directory = opendir($this->_config['save_path'])) === false)) {
			log_message('debug', 'Session: Garbage collector couldn\'t list files under directory \'' . $this->_config['save_path'] . '\'.');
			return $this->_failure;
		}

		$ts = time() - $maxlifetime;
		$pattern = ($this->_config['match_ip'] === true ? '[0-9a-f]{32}' : '');
		$pattern = sprintf('#\\A%s' . $pattern . $this->_sid_regexp . '\\z#', preg_quote($this->_config['cookie_name']));

		while (($file = readdir($directory)) !== false) {
			if (!preg_match($pattern, $file) || !is_file($this->_config['save_path'] . DIRECTORY_SEPARATOR . $file) || (($mtime = filemtime($this->_config['save_path'] . DIRECTORY_SEPARATOR . $file)) === false) || ($ts < $mtime)) {
				continue;
			}

			unlink($this->_config['save_path'] . DIRECTORY_SEPARATOR . $file);
		}

		closedir($directory);
		return $this->_success;
	}

	static protected function strlen($str)
	{
		return self::$func_overload ? mb_strlen($str, '8bit') : strlen($str);
	}
}

?>
